media-db: Fix problems introduced by upgrade bug
media-db: Fix problems introduced by upgrade bug

This patch checks if there is an UNIQUE constraint on the object_fk column
of meta_data and if not re-creates the table forcing a full re-index.

Tarnyko/rygel,Tarnyko/rygel,jku/rygel,jku/rygel,luisbg/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,Pelagicore/Media-Manager-Rygel-patched